Prosthesis

ABSTRACT

The invention relates to prostheses for amputated patients. The shaft of the prosthesis has an outer shell and a concentric inner shell. Both shells are provided with longitudinal slits which are staggered in relation to each other and extend essentially in an axial direction. The diameter of the shaft of the prosthesis can be adjusted by tightening elements. An adaptor is fixed in the shaft of the prosthesis in such a way that the height of the adapter can be adjusted. A conical bearing surface for the stump of the limb is provided on the upper side of the adapter, a holding element for fixing an artificial limb is provided on the lower side of the same, and a coupling is provided inside the adapter for detachably fixing the coupling pin of a commercially available silicone liner.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to prostheses including a silicone linerwith a coupling pin, a prosthesis shaft adapted to a limb stump,provided with longitudinal slits in portions thereof, the diameter beingadjustable by tightening elements, and a holding device to connectartificial limbs with the shaft of the prosthesis.

2. Description of the Background Art

The purpose of prostheses is to replace, as best as possible, limbs thatwere lost through an accident or illness. To temporarily attachprostheses, for example artificial hands or feet, to a limb stump,special prosthesis shafts are used, which must be anatomically fitted tothe limb stump. The attachment is commonly achieved by a vacuum betweenthe prosthesis shaft and the limb stump or between the limb stump and asilicone liner.

Prosthesis shafts are made of metal, wood or cast resin. There areshafts of longitudinal or cross-oval shape, full-contact shafts, with avalve, or a silicone liner. With amputations below the knee joint, theprosthesis shafts are somewhat triangle-shaped, with support devices onthe bone structure.

Since the prosthesis shafts must be fitted to the limb stump as exactlyas possible, in order to generate and maintain the vacuum providing thefirm attachment, the shafts are always custom-made products, which alsomust provide perfect pressure distribution of the load onto the entirestump area so that the stump can optimally transfer the body weight andother forces. Since initially after an accident or amputation, there isswelling of the limb stump within a few days or weeks, which then goesdown again, but from a medical and orthopedic view, the patient shouldbe fitted with a prosthesis as quickly as possible, at times severalprosthesis shafts must be fabricated individually during therehabilitation and adjustment period alone. This is unsatisfactorybecause of the expenditure of time and particularly money connectedtherewith.

It goes without saying that there has been no lack in attempts torectify this situation. For example, inflatable air chambers have beenarranged between the prosthesis shaft and the limb stump, see WO00/23016. However, it was determined very quickly, that the gripattachment of the prosthesis to the limb stump was clearly reduced. Inparticular, the utilization value of the prosthesis was greatly reduced,since it is not solidly connected to the limb stump anymore.

To circumvent this problem, DE 27 18 395 C suggests filling air chamberswith little balls. The ball-filled air chambers are supposed to adapt tothe contours of the limb stump. By evacuating the air chambers, theballs are supposed to be molded into their actual, more or lesswell-adapted, position on the limb stump. Although it was good thinking,this construction did not prove itself and was not successful inpractice.

From DE Patent 314 985, which was published in 1919, a prosthesis shaftis known, which is made of an inner and an outer shell. The inner andouter shell consists of individual lamellae, which are connected to eachother by a rivet, in such a way that the diameter of the inner and outshell can be modified. To alter the diameter of the inner and outershell, several tightening strings are provided. However, after closingthe tightening strings for the outer shell, the tightening strings forthe inner shell are no longer accessible, that is, their fasteners arenot accessible anymore. Attaching and detaching of such a prosthesisshaft is, therefore, extremely cumbersome and time-consuming. Inaddition, prosthesis shafts made of lamellae cannot develop a vacuum forfirm attachment to the limp stump.

A further, dual-shell prosthesis shaft is known from DE Patent 323 671,which was published in 1920. Here, too, an inner and outer shell consistof lamellae, whereby the lamellae of each shell are mutually connectedby a rivet in such a way that it allows modification of the diameterwith the help of tightening strips. Furthermore, an upper part of thelamellae of the inner shell are movably connected with the lamellae ofthe outer shell. The object of this construction is to avoid gapsbetween the individual lamellae. This construction also did not succeedin practice.

From the orthopedic practice it is known that limb stumps not onlychange in width but also in length. This is, for example, the case whenthe end of the limb stump, which is in direct contact with theprosthesis and, for example, in the case of an upper thigh prosthesis,must bear the entire body weight of the patient, gets infected andswelling occurs. A change in length can also occur when the swollentissue is healing after an amputation or operation, and the swellinggoes down. The limb stump then no longer sits correctly with a conicalbearing surface that is provided in each prosthesis shaft and can, forexample, no longer optimally transfer the body weight to the prosthesis.Also, in this case, new prosthesis shafts must be fabricated or the oldprosthesis shafts must be modified. This is unsatisfactory.

From DE 82 16 840 U a prosthesis shaft is known, whereby a height of theconical bearing surface for the limb stump is adjustable. The heightadjustment is done using level or wedge mechanics, which can bemanipulated from the outside by the patient using a crank or somethingsimilar. Height adjustment with a built-in electric motor, possiblybattery-operated, is also suggested. Since the height adjustment must beinstalled in the custom-made prosthesis shaft, it must be enlarged andmodified accordingly. This increases the expenditure of time and money.

As previously mentioned, each prosthesis shaft must be fabricated insuch a way that it transfers the forces optimal to the limb stump. Toaccomplish this, the prosthesis shaft must be suitably inflexible. Inorder to be able to adjust the diameter, the prosthesis shaft must beflexible. Flexibility directed towards the diameter can be achieved byconstruction with lamellae, as described in the German patents listedabove. The connection between the lamellae with only one rivet, however,has the disadvantage that it weakens the stability of the prosthesisshaft.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide aprosthesis as previously described, which can be fabricated simply andthanks to prefabrication can be produced in greater series,cost-efficiently, having a great solidity and fits within predeterminedlimits to limb stumps, whereby a diameter and length can be changed.

The prosthesis includes: a silicone liner with a coupling pin; aprosthesis shaft that is fitted to a limb stump and provided withlongitudinal slits in some areas, and is adjustable in diameter usingtightening elements. A fastener is provided for connecting an artificiallimb with the prosthesis shaft. The longitudinal slits are bridged overand the prosthesis shaft has a concentric band. Inside the band, acylindrical adaptor is height-adjustably mounted. The adaptor has at itsupper end a bearing surface for the limb stump or an end of the siliconeliner and a fastener at the bottom, and on its inside a coupling fordetachable fixation of the coupling pin at the top and mechanics forloosening the coupling at the bottom.

According to the present invention, the flexibility of the prosthesisshaft is achieved by the longitudinal slits, the inflexibility of theslitted prosthesis shaft by bridging the longitudinal slits. Thanks tothe considerably improved stiffness, the wall strength can be decreasedand thus, comfort of wearing can be increased. The adjustability of thediameter of the prosthesis shaft makes it possible, through industrialprefabrication of only a few basic models for the right and the leftside of the body, respectively, to meet the demand for most of thecommon initial provisions. Moreover, the prosthesis can be attached anddetached quickly and comfortably. Its fit is impeccable.

To attach the prosthesis, the silicone liner is first rolled over thelimb stump. Next, the limb stump and silicone liner must be insertedinto the prosthesis shaft of the prosthesis, until the end of the limbstump or the silicone liner rests on the conical bearing surface,whereby the coupling pin is completely immersed in the coupling. Whenthe prosthesis shaft fits very tightly, for example, because the limpstump is slightly swollen, it can happen with a one-piece prosthesisshaft that the optimal position is not achieved. For this reason,current commercial prostheses have an installed freewheeling gear wheel,which the wearer of the prosthesis can manipulate from the outside witha coin. This gear wheel interacts with the profiled coupling pin, whichin this way is pulled into the prosthesis shaft. In contrast thereto,with the prosthesis of the present invention, such a construction isentirely superfluous, because any limb stump can be inserted into theopen prosthesis shaft without any difficulty. The same is true for thedetachment of the prosthesis.

As soon as the patient no longer needs the interim prosthesis of thisinvention, it can be cleaned and used for the next patient. Thereduction of resources and expenses connected therewith is, to date,unmatched.

The ability to industrially prefabricate the interim prosthesis of theinvention in few sizes is, by the way, only possible because theprosthesis of this invention not only has a width adjustment but also alength adjustment in the form of a cylindrical adaptor, which isinserted, more or less as needed, into the prosthesis shaft. Thisadaptor has, at its top, the conical bearing surface for the limb stump,at its bottom the standard coupling for fastening an artificial limb,and on its inside the mechanics for detachably fastening the couplingpin and commercial silicone liner.

According to a first embodiment of the invention, the longitudinal slitsare at least partially bridged, e.g., spanned, with a flexible material,which forms ripples and folds. These ripples and folds can be made ofthe same material that the prosthesis shaft is made of, whereby theflexibility is achieved by careful selection of wall strength and shape.

As an alternative, there is the possibility to bridge the longitudinalslits with a rubber-like material, in particular silicone rubber.

In a preferred embodiment of the invention, the prosthesis shaft isformed by two concentric shells. Therewith, an inner area of the outershell is essentially the same as an outer area of the inner shell, thelongitudinal slits of the outer and inner shells are staggered inrelation to each other, and the diameter of both shells is mutuallyadjustable by tightening elements. Additionally, the inner and outershells have a concentric band, which holds the adaptor.

This embodiment of the invention has a great stiffness, together withlow weight and high comfort in wearing, even with minimal wall strengthsof the shells, which fit each other perfectly, comparably to the skinsof an onion. Since both shells are held in place by one type oftightening element, such a prosthesis is very quickly attached anddetached. Furthermore, this embodiment of the invention can beindustrially prefabricated with a few basic models, which reduces thecost of the prosthesis even further.

According to an advantageous embodiment of the invention, the couplingpin on the silicone liner is a plain cylinder, and the coupling includesa clamping plate and an opening that fits the coupling pin, whereby theclamping plate is pivotably positioned on an axis and is pivoted into aclamp position by springs. Such a smooth coupling pin is not onlysimpler and more cost-effective than a profiled coupling pin, but isalso in all cases easy to detach, as opposed to conventional profiledpins, which are held by a free-wheeling gear wheel, which afterprolonged wearing of the prosthesis is under enormous pre-stress andtends to jam.

Advantageously, the clamping plate, which is positioned in the upperpart of the adapter because of the shortness of the coupling pin, isconnected by a rope or a spoke to a manual lever, which is positioned atthe lower end of the adapter and is thus easily accessible at everyheight adjustment. Basically, this coupling construction also works withthe commercial profiled coupling pins, however, the height adjustment isthen not progressive.

Advantageously, the adapter includes two parts, which are held togetherby screws or the like. In an advantageous embodiment, one of thefastening screws can be simultaneously used as a pivotal axis for theclamping plate of the coupling.

The connection between the inner and outer shells and the adapter ispreferably performed with a clamp connection. In order to achieve a safeclamp connection between the prosthesis shaft and the adapter it issuggested to slit the band elastically.

In a preferred embodiment, the clamp ring itself has a flange formounting the tightening screws.

As mentioned, the adaptor of this invention allows adaptation to limbstumps of varying lengths or to those that had to be shortened formedical reasons, without having to change the actual prosthesis shaft.Only the connection rod between the artificial limb and the conventionalfastener, which is positioned at the lower end of the adapter, has to beextended.

According to an embodiment of the invention, the mechanics for detachingthe coupling includes a manual lever, which is retractable, so that itdoes not get in the way when the prosthesis is being worn.

Advantageously, the shells of the prosthesis shaft are made offiber-reinforced, particularly carbon fiber-reinforced, plastic, wherebythe reinforced fibers essentially extend in an axial direction so that,as desired, there is a high stiffness in an axial direction andsufficient flexibility in a circumferential direction.

In a case, where the longitudinal slits in the outer or inner shellbother the patient, these can, at least partially, be filled with aflexible material. This flexible material can be a rubber-likesubstance, for example, silicone rubber.

In order to be able to attach and detach the prosthesis of the inventionvery quickly, the tightening element is preferably a tightening bandwith a toggle latch closure.

To prevent vascular congestion in the limb stump because the tighteningband is too tight, or because the prosthesis does not fit-properlybecause the tightening band is not tight enough, the tightening elementis equipped with a length adaptation device, which is to be operatedonly by an expert, for example, an orthopedic technician. Thus, thepatient can only open and close the tightening element.

Lastly, one should make sure that inner shell and outer shell, adapter,and in some cases, clamp ring are safeguarded against twisting.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus, are not limitiveof the present invention, and wherein:

FIG. 1 is a prosthesis shaft according to a preferred embodiment of thepresent invention, which is adjustable in a circumferential and alongitudinal direction;

FIG. 2 is part of the prosthesis shaft of FIG. 1 in enlarged scale, withan inserted adapter in a fully extended position;

FIG. 3 is the adapter of FIG. 2 in a fully immersed position;

FIG. 4 is the adapter of FIG. 2 and 3 in an opened position; and

FIG. 5 shows various cross-sections of folds or ripples.

DETAILED DESCRIPTION

FIG. 1 is a perspective illustration of a prosthesis shaft 10, which isanatomically fitted to a limb stump (not shown), at the bottom of which,a coupling 29, e.g., a holding element, is mounted to which, if need be,an artificial limb, for example an arm or foot prosthesis, can beattached via an extension rod.

The prosthesis shaft 10 includes an outer shell 11 and an inner shell11′. In the outer and inner shells 11, 11′, there are slits 12, 12′extending essentially in an axial direction, which are staggered inrelation to each other. In an ideal situation, the outer and inner shell11, 11′ touch each other like the skins of an onion.

When the outer and inner shell 11, 11′ is made of a carbonfiber-reinforced plastic, thinner walls and thus reduced weight can beachieved. If the reinforced fibers extend mostly in an axial direction,the shells 11, 11′ are inflexible in a longitudinal direction, andflexible in a circumferential direction.

In order to be able to adjust the diameter of the prosthesis shaft 10having the outer and inner shells 11, 11′, two tightening bands 13including toggle catch closures 14 are provided, the width of which canbe adjusted by a precision-adjuster (not illustrated) by a trainedtechnician. When the toggle catch closures 14 are closed, the slits 12,12′ are compressed, which causes a tight fit of the prosthesis shaft 10to the limb stump.

FIG. 1 also illustrates, purely schematically, a silicone liner 40.Initially, this is put over the limb stump and fixedly attached byvacuum. On the underside of the silicone liner 40, there is provided acoupling pin 41, which interacts with a coupling. This coupling islocated inside a cylinder-shaped adapter 20, which is fixatedheight-adjustably in the prosthesis shaft 10 with the aid of a clampring 30. For this purpose, the outer and inner shell 11, 11′ each haveat their lower end a concentric band 15, 15′. Thanks to a slit 16, theband 15, 15′ is elastically flexible. The clamp ring 30 has a flange 31and can be tightened and/or loosened by tightening screws 32.

FIG. 2 shows, in an enlarged scale, a section of FIG. 1. The adapter 20can be seen in a completely extended condition. Furthermore, at thelower end of the adapter 20, a foldable manual lever 23 can be seen,with which the coupling located in adapter 20 can be operated. Furtherdetails will be described with the description of FIG. 4.

FIG. 3 shows the adapter of FIG. 2 immersed completely in the prosthesisshaft 10. Thus, at the upper end of the adapter 20, a conical bearingsurface 21 for the limb stump, that is, the silicone line 40, can beseen.

FIG. 4 shows the adapter 20 in an opened position. At its top, one cansee the conical bearing surface 21, on which the top of the silicone 40rests. Its coupling pin 41 is formed as a smooth cylinder and extendsthrough the bearing surface 21. The coupling includes a clamp plate 22,which is pivotably positioned around an axis 25, and whichsimultaneously serves as a connection screw. Springs 26 pivot the clampplate 22 into a clamp position so that the coupling pin 41 can beinserted without a problem and at the same time is safeguarded againstunintended detachment. Additional screws 31, 32 connect parts of theadapter 20.

To detach the clamp plate 22, the manual lever 23 is used, which isconnected with the clamp plate 22 via a coupler rod 24 and/or a couplerrope located inside the adapter 20. When the patient moves the lever 23downward, the clamp plate 22 is pivoted downward from its clampposition, as illustrated in the drawing, to a neutral position, and thepatient is able to remove the coupling pin 41 with silicone liner 40 andlimb stump from the adapter 20 and/or prosthesis shaft 10, as soon asthe tightening bands 13, 14 are opened. The clamp plate 22 is anordinary, hardened steel plate with a bore, which corresponds with thediameter of the coupling pin 41. This simple construction is extremelydurable and safe to operate.

FIG. 5 shows, purely schematically, three possible cross-sections offolds and/or ripples, with which the longitudinal slits 12 can bebridged, e.g., spanned. These cross-sections are, seen from top tobottom, of zig-zag, omega and dovetail shape. In other words, edgesurfaces of the outer and inner shells 11, 11′, which are formed by thespan of the longitudinal slits 12, 12′, have a cross-section as shown inFIG. 5.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are to beincluded within the scope of the following claims.

1. A prosthesis comprising: a silicone liner having a coupling pin; a prosthesis shaft for being fitted to a limb stump and provided with longitudinal slits in a portion thereof, the prosthesis shaft being adjustable in diameter by tightening elements; and a holding element for connecting an artificial limb with the prosthesis shaft, wherein the prosthesis shaft has a concentric band circumferentially attached thereto, the concentric band having a cylindrical adapter height-adjustably installed therein, wherein the adapter includes a bearing surface at an upper end thereof for receiving the limb stump or the end of the silicone liner and a holding element at a lower end, and wherein the adapter includes in an interior portion a coupling for detachably securing of the coupling pin at the upper end and mechanics for detaching the coupling.
 2. The prosthesis according to claim 1, wherein edge surfaces of the prosthesis shaft that are formed by the longitudinal slits are at least partially spanned by a flexible material, which forms ripples or folds.
 3. The prosthesis according to claim 1, wherein: the prosthesis shaft is formed by an inner shell and an outer shell that are concentric, an inner surface of the outer shell is essentially the same as an outer surface of the inner shell, the longitudinal slits of the outer and inner shells are staggered in relation to each other, the diameter of the inner and outer shells are mutually adjustable by a tightening element, and the outer and inner shells contain the concentric band.
 4. The prosthesis according to claim 3, wherein the inner and outer shells are made of fiber-reinforced plastic.
 5. The prosthesis according to claim 4, wherein the reinforced fibers extend essentially in an axial direction.
 6. The prosthesis according to claim 4, wherein the fiber-reinforced plastic is carbon fiber-reinforced plastic.
 7. The prosthesis according to claim 3, wherein the longitudinal slits in the outer shell and/or the inner shell are at least partially bridged by a rubber-like material.
 8. The prosthesis according to claim 7, wherein the rubber-like material is silicone rubber.
 9. The prosthesis according to claim 3, wherein the inner shell, the outer shell, the adapter, and the clamp ring are safeguarded against contortion.
 10. The prosthesis according to claim 1, wherein: the coupling pin is a smooth cylinder, and wherein the coupling comprises: a clamp plate with an opening, which is fitted for the coupling pin; an axis, on which the clamp plate is pivotally positioned; and springs, which pivot the clamp plate into a clamp position.
 11. The prosthesis according to claim 10, wherein the adapter includes two parts, and wherein the axis simultaneously serves as a connection element.
 12. The prosthesis according to claim 10, wherein the mechanics for detaching the coupling include a manual lever, and wherein the manual lever is foldable.
 13. The prosthesis according to claim 1, wherein the concentric band is elastically slitted.
 14. The prosthesis according to claim 1, wherein a clamp ring is mounted onto the concentric band.
 15. The prosthesis according to claim 14, wherein the clamp ring has a flange for mounting clamp screws.
 16. The prosthesis according to claim 1, wherein the tightening element has a tightening band with a toggle latch closure.
 17. The prosthesis according to claim 1, wherein the tightening element has a length adjustment.
 18. The prosthesis according to claim 17, wherein the tightening element is manually operable.
 19. The prosthesis according to claim 1, wherein the tightened by the tightening elements.
 20. A prosthesis comprising: a prosthesis shaft for receiving a limb stump, the prosthesis shaft including an inner shell and an outer shell that has longitudinal slits provided therein for enabling a diameter adjustment of the prosthesis shaft about the limb stump; and an adapter being height adjustably and securely attached to the prosthesis shaft at an upper end of the adapter, the adapter having a holding element provided on a lower end for attachably receiving an artificial limb, and the adapter having a coupling for releasably securing a coupling pin, the coupling pin being connectable to the limb stump.
 21. The prosthesis according to claim 20, wherein a tightening band, which is provided substantially circumferentially about the prosthesis shaft, enables the diameter adjustment.
 22. The prosthesis according to claim 20, wherein the height of the adapter, in relation to the prosthesis shaft, is adjusted by an adaptive securing of the adapter via an adjustable concentric band that is fixedly provided on the prosthesis shaft.
 23. The prosthesis according to claim 20, wherein the pin is connectable to the limb stump by a silicon liner. 